esnext.async-iterator.take.js
1017 Bytes
'use strict';
// https://github.com/tc39/proposal-iterator-helpers
var $ = require('../internals/export');
var anObject = require('../internals/an-object');
var toPositiveInteger = require('../internals/to-positive-integer');
var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg, Promise) {
var iterator = this.iterator;
var returnMethod, result;
if (!this.remaining--) {
result = { done: true, value: undefined };
this.done = true;
returnMethod = iterator['return'];
if (returnMethod !== undefined) {
return Promise.resolve(returnMethod.call(iterator)).then(function () {
return result;
});
}
return result;
} return this.next.call(iterator, arg);
});
$({ target: 'AsyncIterator', proto: true, real: true }, {
take: function take(limit) {
return new AsyncIteratorProxy({
iterator: anObject(this),
remaining: toPositiveInteger(limit)
});
}
});